ZIMBABWE SCHOOL EXAMINATIONS COUNCIL General Certificate of Education Ordinary Level COMBINED SCIENCE 4003/3 PAPER 3 Practical Test SPECIMEN PAPER 1 hour 30 minutes Candidates answer on the question paper Additional materials: As listed in instructions to Supervisors Calculator (optional) 30 cm ruler TIME 1 hour 30 minutes INSTRUCTIONS TO CANDIDATES Write your name, centre number and candidate number in the spaces at the top of this page. Answer both questions. Write your answers in the spaces provided on the question paper. Use a sharp pencil for your drawings. Coloured pencils or crayons should not be used. You should show the essential steps in any calculation and record all experimental results in the spaces provided in the question paper. FOR EXAMINER’S USE INFORMATION FOR CANDIDATES The number of marks is given in brackets [ ] at the end 1 of each question or part question. 2 TOTAL ___________________________________________________________________________ This question paper consists of 5 printed pages and 3 blank pages. Copyright: Zimbabwe School Examinations Council, Specimen paper. ZIMSEC Specimen paper [Turn over 2 1. You are required to investigate the effect of concentration on plant tissue. You are provided with 5 potato cylinders placed in distilled water, four solutions, A, B, C and D, in beakers, a stop watch and a ruler. The length of each of the five potato cylinders was 5 cm before being placed in distilled water and left over night. (a) (i) Measure the initial length of each of any four cylinders and record it in Table 1.1. Table 1.1 solution initial length /cm final length/cm change in length/cm A B C D [11] Place one potato cylinder in each of the corresponding solutions, A, B, C and D, and immediately start a stopwatch. Leave the apparatus to stand for twenty minutes while you proceed to question 2. After 20 minutes, measure the final length of each cylinder and record it in Table 1.1. Calculate and record the change in length in Table 1.1. (ii) Beside the change in length, state any other observation made between potato cylinders in distilled water and those from the solutions. ___________________________________________________ ___________________________________________________ ___________________________________________________ 4003/3 Specimen paper [1] 3 b (i) Identify, giving a reason, the solution with the potato cylinder which lost the most water. solution_______________________________________________ reason _______________________________________________ _______________________________________________ (ii) [2] Name the process that led to the changes observed. _____________________________________________________ _____________________________________________________ (c) [1] Plot a graph of change in length of the potato cylinders against the solution. change in length/cm [3] A B C D solution 4003/3 Specimen paper [Turn over 4 (d) Suggest two ways of improving the experiment. 1._________________________________________________________ 2._________________________________________________________ [2] [Total:20] 2. You are required to compare the reactivity of two metals A and B, by reacting each metal with dilute hydrochloric acid, HCl. You are provided with two test tubes labelled A and B, a thermometer, a test tube rack, a measuring cylinder, dilute hydrochloric acid, metal A and metal B. (a) Measure 5 cm3 of dilute hydrochloric acid and pour it into the test tube labelled A. (i) Measure 5 cm3 of the dilute hydrochloric acid and pour it into the test tube labelled B. Place metal A into test tube A and metal B into test tube B at the same time. Record, in Table 2.1, all the observations made in each of the test tubes, clearly stating any differences observed. Table 2.1 Observations in test tube A 1. Observations in test tube B 2. 3. 4. [11] 4003/3 Specimen paper 5 (a) (ii) Measure the temperature of the solutions in test tubes A and B and compare them. _____________________________________________________ _____________________________________________________ _____________________________________________________ (iii) [2] Suggest two other factors that should be maintained to make the comparison of the results fair. _____________________________________________________ _____________________________________________________ (b) [2] State the general products of the reactions. ___________________________________________________________ ___________________________________________________________ (c ) [2] State, with a reason, the metal which is more reactive. ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ (d) [2] State one precaution that should be taken during the experiment. ___________________________________________________________ ___________________________________________________________ [1] [Total:20] 4003/3 Specimen paper 6 BLANK PAGE 4003/3 Specimen paper 7 BLANK PAGE 4003/3 Specimen paper 8 BLANK PAGE 4003/3 Specimen paper